Peritoneal dialysis is accomplished by means of a flexible catheter implanted so as to pass directly through the skin and peritoneal wall into the peritoneal cavity. In its most common practice, continuous peritoneal dialysis involves connecting the body exterior end of the catheter to a plastic bag of dialysate solution which is drained into the peritoneal cavity. The bag and catheter connecting tubes are wrapped around the body of the patient during the dialysis interval, remaining connected to the catheter. At the end of the dialysis interval, the bag is dropped and the used dialysate is drained back into the bag by gravity. After drainage is completed, a fresh bag of dialyzate is connected to the catheter and the cycle repeated. A recent detailed review of devices associated with peritoneal dialysis may be found in Ward et al, "Investigation of the Risks and Hazards with Devices Associated with Peritoneal Dialysis (including Intermittant Peritoneal Dialysis and Continuous Ambulatory Peritoneal Dialysis) and Sorbent Regenerated Dialysate Delivery Systems", Revised Draft Report for FDA Contract No. 223-81-5001 (June 1982).
Despite extensive protocols for maintaining sterility, infection frequently occurs as a result of peritoneal dialysis. The most common infection pathway is through the interior of the catheter but exit site infection caused by bacteria invasion along the exterior surfaces of the catheter occurs as well.
Improvements in peritoneal dialysis implants are described in co-pending applications Ser. No. 314,569, filed 10/26/81 U.S. Pat. No. 4,417,888, issued Nov. 29, 1983 which have a common assignee with the present application. The improvements of these prior applications comprise rigid tubular percutaneous devices implanted through the skin to which a catheter member is affixed subcutaneously. The percutaneous devices of these applications are preferably septum closed with access to the peritonium accomplished through a sterile needle assembly. The rigid tubular configuration of the percutaneous device provides substantial benefits in minimizing exit site infection, in part, by providing a structure less subject to attack by body fluids. The percutaneous device is preferably made of titanium which may be coated with vapor deposited carbon or other biocompatible coatings. The preferred septum closure of these devices together with needle access provides an improved infection barrier through the interior of the device. The septum closure is especially advantageous in eliminating most risk of infection through accidental disconnection or damage to the catheter connections. When the needle is removed either accidentally or between dialysis cycles, the septum automatically closes maintaining the aseptic condition. The closure is below the skin reducing the possibility of damage to the catheter portion of prior devices which extend through the skin for an inch or more.